In this journal the authors describe an experiment where the students attempt to measure the acceleration due to gravity (g). In this experiment the main apparatuses are as follows:
LED-unit whose flash oscillates
Meter stick for reference/measurement
Digital Camera with long-exposure
The students work in groups of two (2) for best results. One student holds the flashing LED apparatus while the other holds a meter stick with a red LED on the top and bottom for reference. The teacher operates the digital camera and makes sure that the camera is using a ~2 second exposer. When the students and teacher are ready the teacher will begin the long-exposure picture. The student who is holding the LED apparatus will drop the unit from the top of the meter stick. After this is completed the teacher will enlarge the picture on (for example) a projector screen so the students can see their picture. An example of their picture should look like this:
From here the students will collect data from their picture and put the data into two (2) collumns. One being the position of the falling LED and the other being "time" (the LED flashes in equal intervals so the information they put into the time collumn should be multiples of the frequency of the flash. The students will then have a graph of the accelleration of the LED object as it falls. Using a curve fitting program the students can approximate g.
Reflection:
This experiment is a 21st century representation of a 17th century problem. Just as Newton observed an apple falling from a tree, the students will be able to observe and VIEW an object falling from their hand. This is accomplished by LED technology allowing us to create extremely small and CHEAP (key-word) LED apparatuses to drop. While only requiring one (1) camera to collect data. The students will be able to both experience and analyze data with the help of modern technology. By using computer to collect data and computer-software to graph and fit data, students will gain knowledge in how modern computer software will allow them to analyze any set of data.
What I enjoy most about this experiment-journal is that it poses many different levels of outcome for both teachers and students. This experiment appears enjoyable for any high school student due to the level of technology involved (especially computers). Also, for lower level physics classes the teacher can limit the experiment to simply distance (x) and time (t) as described above. However, for higher level classes the teacher can have the students use their experimental value of g to compute the velocity of the LED object as it falls through the air. Then they can plot the velocity versus time and check to see if the velocity is truely increasing at a constant rate. In conclusion, i feel the possibilities for this experiment are endless and the motivation behind it is a given.
Summary:
In this journal the authors describe an experiment where the students attempt to measure the acceleration due to gravity (g). In this experiment the main apparatuses are as follows:
The students work in groups of two (2) for best results. One student holds the flashing LED apparatus while the other holds a meter stick with a red LED on the top and bottom for reference. The teacher operates the digital camera and makes sure that the camera is using a ~2 second exposer. When the students and teacher are ready the teacher will begin the long-exposure picture. The student who is holding the LED apparatus will drop the unit from the top of the meter stick. After this is completed the teacher will enlarge the picture on (for example) a projector screen so the students can see their picture. An example of their picture should look like this:
From here the students will collect data from their picture and put the data into two (2) collumns. One being the position of the falling LED and the other being "time" (the LED flashes in equal intervals so the information they put into the time collumn should be multiples of the frequency of the flash. The students will then have a graph of the accelleration of the LED object as it falls. Using a curve fitting program the students can approximate g.
Reflection:
This experiment is a 21st century representation of a 17th century problem. Just as Newton observed an apple falling from a tree, the students will be able to observe and VIEW an object falling from their hand. This is accomplished by LED technology allowing us to create extremely small and CHEAP (key-word) LED apparatuses to drop. While only requiring one (1) camera to collect data. The students will be able to both experience and analyze data with the help of modern technology. By using computer to collect data and computer-software to graph and fit data, students will gain knowledge in how modern computer software will allow them to analyze any set of data.
What I enjoy most about this experiment-journal is that it poses many different levels of outcome for both teachers and students. This experiment appears enjoyable for any high school student due to the level of technology involved (especially computers). Also, for lower level physics classes the teacher can limit the experiment to simply distance (x) and time (t) as described above. However, for higher level classes the teacher can have the students use their experimental value of g to compute the velocity of the LED object as it falls through the air. Then they can plot the velocity versus time and check to see if the velocity is truely increasing at a constant rate. In conclusion, i feel the possibilities for this experiment are endless and the motivation behind it is a given.
By: David Kenahan
Date: 9-30-08
Amended: 10-18-08